Figure 3 - Flow-related increases in a-phenyl-N-tert-butylnitrone (PBN) radical adduct yields in endothelialized aortas in the control (Control) condition and after treatment with L-NMMA (N = 4), D-NMMA (N = 4) and L-arginine + L-NMMA (N = 3). Data with L-NAME (N = 5) were previously published (9) and are shown only for comparison. Both L-NMMA and D-NMMA completely blocked radical generation. L-arginine did not reverse the blockade. *P<0.02 vs baseline. The SNK multiple range test showed that the control group was different from all groups, except for L-NAME. The D-NMMA group did not differ from the L-NMMA or L-arg + L-NMMA group. Data are reported as means ± SEM.